A Viking lesson in pirating takes a strange turn when Hiccup and his best friend, Fishlegs, accidentally raid the wrong ship while trying to escape Sharkworms. The two lads rescue a tiny yet arrogant nanodragon named Ziggerastica, but then they are kidnapped as part of a vicious plot to steal every dragon on the Isle of Berk! Hiccup must rely on his tiny new friend, and his ability to speak Dragonese, to save the day ... again!